Easton Diversion Dam


Easton Diversion Dam located on the Yakima River near Easton, is a concrete gravity ogee weir, movable crest structure. This dam is 66 feet high and contains 5,800 cubic yards of concrete.

Intensive Federal, State, tribal, and local efforts in conjunction with the Northwest Power Planning Council resulted in Congress authorizing implementation of Phase I of the Yakima River Basin Water Enhancement Project in 1984. The purpose of Phase I is to reduce anadromous fish mortality at outdated fish ladders at diversion dams and inadequate fish screens at diversion canals. Ladders and screens at the largest diversion dams and canals were completed in 1989 and a similar program is underway at the smaller diversions.

RegionFacilities in Pacific Northwest | Pacific Northwest Home Page
Dam TypeConcrete Gravity
ReservoirLake Easton
WatercourseYakima River
Original Construction1928-1929
Modified Construction
National ID NumberWA00279
Hydrologic Unit Code

Structural Height66.0 ft
Hydraulic Height (Normal Operating Depth at Dam)43.0 ft
Top Parapet (Elevation)
Spillway Crest Elevation2181.0 ft
Crest Elevation2184.5 ft
Crest Length248.0 ft
Crest Width
Base Width
Volume of Dam Construction Materials5800 cu yd
Streambed at Dam Axis
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)
Top of Active Conservation Pool (Elevation)2181.0 ft
Top of Inactive Conservation Pool (Elevation)
Top of Dead Storage Pool (Elevation)

Hydraulics & Hydrology
Total Water Storage at Elevation3,992 ac-ft
Maximum Water Surface Elevation
Normal Water Surface Elevation2181.0 ft
Spillway TypeOverflow Drum Gate
Auxiliary Spillway
Spillway Capacity at Elevation13,000 cfs
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation1,320 cfs
Diversion Capacity at Elevation
Drainage Area
Hydrometeorological Report (HMR)
Probable Maximum Flood (PMF) Report

Contact Information
TitleArea Office Manager
OrganizationColumbia-Cascades Area Office
Address1917 Marsh Road
CityYakima, WA 98901-2058
Phone (Fax)509 454-5611
Phone (Office)509 575-5848 x202
OrganizationKittitas Reclamation District
AddressPO Box 276
CityEllensburg, WA 98926-0276
Phone (Office)509 925-6158

Last updated: Mar 27, 2009